Light-sensitive layer



45 sulio-, dimethyl-amino groups or the like.

Patented Nov. 28, 1933 V UNITED" sures PATENT oFFIcE I LIGHT- SENSITIVE LAYER Maximilian Paul Schmidt, Wilhelm Krieger, and Eduard Spriingerts, Wiesbaden-Biebricli, Ger! many, assignors to Kalle 8; Co. Aktiengesellschaft, Wiesbaden-Biebrich, Germany No Drawing.

Application November 30, 1928,

" Claims.

The present invention relates to light-sensitive layers.

In the preparation of positive diazo-types from positive originals, light-sensitive layers are used, 5 which contain a stable diazo compound and an azo component. Furthermore, positive diazotypes can be obtained by using light sensitive layers containing diazo compounds alone, and exposing them to light at first under a design 10 and then for a short time in a free state, that is, without using a design (see U. S. Patent No. 1,444,469 to Gustav Kogel and Heinrich Neuenhaus dated February 6, 1923). However this process yields contingent results due to the double exposure to light. We have now found that in a simple manner positive diazo-prints from positive originals are obtained by using diazo compounds which are stable in a neutral or an acid solution, but which in the presence of alkali are capable of coupling directly with themselves without being subjected to the action of light. These diazo compounds also possess the property of azo components. Among the compounds in question, those diazo compounds are particularly useful which contain one or several hydroxyor amino groups, situated in a nucleus different from that containing the diazo group. Such diazo compounds are, for instance, produced from the amino-hydroxynaphthalenes such as 1-amino-8-hydroxynaphthalene-3-6-disulfonic acid (H-acid) 2-amino-5- hydroxynaphthalene-l-sulfonic acid (J -acid), or from amino-hydroxynaphthalenes having a diazotizable group attached to the nitrogen. It is, however, likewise possible to use diazo anhydrides, that is to'say, aromatic diazo compounds, being substituted by at least one hydroxyor amino group in orthoor para-position to the diazo-group, and besides this containing at least one or more additional hydroxyor aminogroups preferably being attached to a nucleus different from that containing the diazo group. The diazo compounds may also have further substituents, such, for instance, as the methyl-, methoxy-, The hydroxy group may also be acylated, the acyl rest must, however, be easily saponifiable by means of an alkali. For example, the diazo compound may contain an O-CO-CH3 group in"the the base inanacid or neutral medium.

It is to be understood that the process may be carried out with all the various modifications practiced in the art of preparing diazo-types.

nucleus. The diazo compounds are applied on Thus, for instance, a stabilizer or a metallic salt may be added to the layers.

In the German Patent No. 111,416 to Marcel Schoen, dated April 13, 1899, there has already been described a process of obtaining from a posi- 6Q tive picture a negative one or vice versa, by using a light sensitive layer containing a diazotized ortho-aminosalycylic acid which is'applied on a base in an alkaline condition. Contrary thereto, according to the present process a positive is 5 directly obtained from a positive. The diazosalycylic acid does not belong to the class of compounds claimed in our presentapplication,because it is not capable of directly coupling with itselfin an alkaline solution. But, by the' action of 7 light, the diazo-salycylic acid is transformed into a component capable of being coupled. Therefrom it follows that the process of the German Patent No. 111,416 above referred to consists in transforming by the action of light the diazo-- 7 salycylic acid partly into a component capable of being coupled. Due'to the presence of the alkali, this component formed by the action of light'immediately couples with the non-transformed diazo-salycylic acid whereby the picture s is formed at the places which have been exposed to light.

The following examples illustrate our invention, but they are not intended to limit it thereto; the parts are by weight. 8

(1) 30 parts of diazotized'H-acid are dissolved in 1000 parts of water with addition of 50 parts of tartaric acid and the solution is applied as usual on paper, films or the like.

After exposure to light under a positive and development in gaseous ammonia, reddish-violet positive copies are obtained. Copies prepared in the aforesaid manner can, of course, also be developed in alkaline solutions. I

(2) A. solution is prepared of 6 g of tartaric acid and 4 g of thediazo compound obtained in the usual manner from the 1'-amino-4'-piperidyl-3'- benzoyl-lamino -8-hvdroxynaphthalene-3.6-di- J sulfonic acid in 15o cc. of water. The said amine of the formula:

' H OH NET-C 0- 2 a Bots so 11 H is obtained in the following manner: 1-amino-8- hydroiw-naphthalene-3-6-disulfonic acid is condensed with 1-nitro-4-chloro-3-benzoylchloride; the condensation product is caused to react with piperidine and the nitro compound is reduced in the usual manner.

The solution is applied on a; suitable base, for instance on paper or a film, andthebase is dried. After exposure to light under a positive and development with: gaseous ammonia, a bluishviolet picture is obtained.

(3) 3 g. of the double salt of zinc chloride and 2-diazo-7-=hydroxynaphthalene and 4 g of tar-,- taric acid are dissolved in 100 com of water. The solution is spread on a base. After drying, exposure to light under a positive and development with an alkali, a reddish picture is obtained.

position and is therefore capable of couplingwith I itself. I

2. Light sensitive layers containing on a suitable base as single coloring matter an aromatic diazo compound which contains .at least two benzene nuclei and in the benzene nucleus not containing the diazo group at 'least one hydroxyl group, whichmay be substituted and one free coupling position and is therefore capable of coupling with itself. v

3. Light-sensitive layers containing on a suitable base as single coloring matter an aromatic diazo compound which contains at least two benzene nucleiand in the benzene nucleus not containing the diazo group at least one O-acyl group I and one free coupling position and is therefore capable of coupling with itself.

4. Light-sensitive layers containing on a suitable base as single coloring matter an aromatic diazo compound which contains at least two benzene nuclei and in the benzene nucleus not containing the diazo group atleast one O.CO.CH:

group and one free coupling position and is therefore capable of coupling with itself.

5. Light-sensitive layers containing on a-suitable base as single coloring matter an aromatic diazo compound which contains at least two benzene nuclei and in the benzene nucleus not containing the diazo group at least one amino group and one free coupling position and is therefore capable of coupling with itself.

MAXIMILIAN PAUL SCHMIDT.

WILHELM KRIEGER.

EDUARD spnonana'rs. 

